Optical system design of a DMD-SHS combined modulation interference spectrometer

Digital micromirror device (DMD) and spatial heterodyne spectroscopy (SHS) combined modulation interference spectroscopy (DMD-SHS) introduces a DMD for the secondary modulation of interferometric data to achieve a Hadamard transform. DMD-SHS can improve the performance index of the spectrometer in terms of the SNR, dynamic range, and spectral bandwidth, while retaining the advantages of a conventional SHS. The DMD-SHS optical system is more complex than a traditional SHS, which places more demands on the optical system's spatial layout and the optical components' performance. According to the DMD-SHS modulation mechanism, the functions of the main components were analyzed, and their design requirements were determined. Based on the potassium spectra detection, a DMD-SHS experimental device was designed. The potassium lamp and integrating sphere detection experiments demonstrated the detection capability of the DMD-SHS experimental device with a spectral resolution of 0.0327 nm and a spectral range of 763.66 similar to 771.25 nm, which thoroughly verified the feasibility of DMD and SHS combined modulation interference spectroscopy. (c) 2023 Optica Publishing Group